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9152188 Feb 19, 2018
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@miloyip @corporateshark @luzpaz
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// JSON to JSONx conversion example, using SAX API.
// JSONx is an IBM standard format to represent JSON as XML.
// https://www-01.ibm.com/support/knowledgecenter/SS9H2Y_7.1.0/com.ibm.dp.doc/json_jsonx.html
// This example parses JSON text from stdin with validation,
// and convert to JSONx format to stdout.
// Need compile with -D__STDC_FORMAT_MACROS for defining PRId64 and PRIu64 macros.
#include "rapidjson/reader.h"
#include "rapidjson/stringbuffer.h"
#include "rapidjson/filereadstream.h"
#include "rapidjson/filewritestream.h"
#include "rapidjson/error/en.h"
#include <cstdio>
using namespace rapidjson;
// For simplicity, this example only read/write in UTF-8 encoding
template <typename OutputStream>
class JsonxWriter {
public:
JsonxWriter(OutputStream& os) : os_(os), name_(), level_(0), hasName_(false) {
}
bool Null() {
return WriteStartElement("null", true);
}
bool Bool(bool b) {
return
WriteStartElement("boolean") &&
WriteString(b ? "true" : "false") &&
WriteEndElement("boolean");
}
bool Int(int i) {
char buffer[12];
return WriteNumberElement(buffer, sprintf(buffer, "%d", i));
}
bool Uint(unsigned i) {
char buffer[11];
return WriteNumberElement(buffer, sprintf(buffer, "%u", i));
}
bool Int64(int64_t i) {
char buffer[21];
return WriteNumberElement(buffer, sprintf(buffer, "%" PRId64, i));
}
bool Uint64(uint64_t i) {
char buffer[21];
return WriteNumberElement(buffer, sprintf(buffer, "%" PRIu64, i));
}
bool Double(double d) {
char buffer[30];
return WriteNumberElement(buffer, sprintf(buffer, "%.17g", d));
}
bool RawNumber(const char* str, SizeType length, bool) {
return
WriteStartElement("number") &&
WriteEscapedText(str, length) &&
WriteEndElement("number");
}
bool String(const char* str, SizeType length, bool) {
return
WriteStartElement("string") &&
WriteEscapedText(str, length) &&
WriteEndElement("string");
}
bool StartObject() {
return WriteStartElement("object");
}
bool Key(const char* str, SizeType length, bool) {
// backup key to name_
name_.Clear();
for (SizeType i = 0; i < length; i++)
name_.Put(str[i]);
hasName_ = true;
return true;
}
bool EndObject(SizeType) {
return WriteEndElement("object");
}
bool StartArray() {
return WriteStartElement("array");
}
bool EndArray(SizeType) {
return WriteEndElement("array");
}
private:
bool WriteString(const char* s) {
while (*s)
os_.Put(*s++);
return true;
}
bool WriteEscapedAttributeValue(const char* s, size_t length) {
for (size_t i = 0; i < length; i++) {
switch (s[i]) {
case '&': WriteString("&amp;"); break;
case '<': WriteString("&lt;"); break;
case '"': WriteString("&quot;"); break;
default: os_.Put(s[i]); break;
}
}
return true;
}
bool WriteEscapedText(const char* s, size_t length) {
for (size_t i = 0; i < length; i++) {
switch (s[i]) {
case '&': WriteString("&amp;"); break;
case '<': WriteString("&lt;"); break;
default: os_.Put(s[i]); break;
}
}
return true;
}
bool WriteStartElement(const char* type, bool emptyElement = false) {
if (level_ == 0)
if (!WriteString("<?xml version=\"1.0\" encoding=\"UTF-8\"?>"))
return false;
if (!WriteString("<json:") || !WriteString(type))
return false;
// For root element, need to add declarations
if (level_ == 0) {
if (!WriteString(
" xsi:schemaLocation=\"http://www.datapower.com/schemas/json jsonx.xsd\""
" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
" xmlns:json=\"http://www.ibm.com/xmlns/prod/2009/jsonx\""))
return false;
}
if (hasName_) {
hasName_ = false;
if (!WriteString(" name=\"") ||
!WriteEscapedAttributeValue(name_.GetString(), name_.GetSize()) ||
!WriteString("\""))
return false;
}
if (emptyElement)
return WriteString("/>");
else {
level_++;
return WriteString(">");
}
}
bool WriteEndElement(const char* type) {
if (!WriteString("</json:") ||
!WriteString(type) ||
!WriteString(">"))
return false;
// For the last end tag, flush the output stream.
if (--level_ == 0)
os_.Flush();
return true;
}
bool WriteNumberElement(const char* buffer, int length) {
if (!WriteStartElement("number"))
return false;
for (int j = 0; j < length; j++)
os_.Put(buffer[j]);
return WriteEndElement("number");
}
OutputStream& os_;
StringBuffer name_;
unsigned level_;
bool hasName_;
};
int main(int, char*[]) {
// Prepare JSON reader and input stream.
Reader reader;
char readBuffer[65536];
FileReadStream is(stdin, readBuffer, sizeof(readBuffer));
// Prepare JSON writer and output stream.
char writeBuffer[65536];
FileWriteStream os(stdout, writeBuffer, sizeof(writeBuffer));
JsonxWriter<FileWriteStream> writer(os);
// JSON reader parse from the input stream and let writer generate the output.
if (!reader.Parse(is, writer)) {
fprintf(stderr, "\nError(%u): %s\n", static_cast<unsigned>(reader.GetErrorOffset()), GetParseError_En(reader.GetParseErrorCode()));
return 1;
}
return 0;
}